Expression device for self-playing pianos



Feb. 20, 1923. 1,446,116 O. A. ERICSON EXPRESSIQN DEVICE FOR SELF PLAYING PIANOS Filed Dec v e, 1920 5 sheets-sheet 1 -5 I as 26 32 25 Feb. 20, 1923. 1,446,116

0. A. ERICSON EXPRESSION DEVICE FOR SELF PLAYING PIANOS Filed Dec. 6, 1920 fisheets-sheet 2 lizz/azzzwi' 0.500; H 5 1015022.

Feb. 20, 1923.- 1 I 1,446,116

' O. A. ERICSON EXPRESSION DEVICE FOR SELF PLAYING PIANOS Filed Dec. 6, 1920 s shets-sheet s a 1 l g -J2Z2/6/2Z0/1 Oscar A 2 m .Tdallflrwhomit magi coj'ncemp: I

' i Be "it: known that 1}, @SCAR? Ai Emosofi H a citizen of the Unitedf St'ates, i esidin at? j 'Ghicagdg', in the "county IOf-Cook and;

,e p layi l 1g of a mhsichlij'COmpQSitiOIi -in- 0011 fformlty -wlth the warm-b10118} anel lshad ngigf' T 1 vqlume; tone; eta-gas lnd eated orplfBSCrlbed r'aienea; e "i: 1

OF' CHieAGdJ'IiiQINOIS," ASSIGNIJR; i150": W.', w;; kIMSALDCQMMm E v of Illinois; haveinventedieel tain new; anai.

' "useful Improvements 1n 1; Expresslon fOHOWlIlg. 1s a sp e clfiea t on g ThlSdDVQIltlOII relatesto h as expresslon devlc'es l sedw'on' 'elect'r c or re f preclucingjpiano sto-automatically efieefi the v 7 line of and c by .the 1 original c m os 'mr" armpger Ofihe comp'ositiOh. Thesei'expnession devices, so

a perforated music. ishe'et the latter jhaving app1-opriate1y located slots ice-operating 7 I ,,-Whi'ch,1atfier inl turn, throl'ighi suitahle akes; govern the volume :and; 'powelflo fthe eX-- haust created infthe wind chest by-ytghej bel- ,zone object pf; th

Which latterair; is admitted tok pn eilmaticggfl flowswor exhau sters;

previde' a J simple and compact; expression devicewhi'eh mayreadi ly and convenien'tly lows; bf; the latter, and Without involviiig:

I eny z'modification or alteration of ihe pl ayer effect-s from pianissimo I instantly responsive to ;the 0011131701,; f;;the

record sheet in the y-i'eldiliggof 'saidl'effects. A further obj eat" is Qto pIfQVide' an expression; device "equi pped with an n automatic" stabil izer; (fer normally; maintaining. ,a. 'suhs'tenv pable of producing a, @Wiidg range of; dynamic f; fOIUS S IIII O', and

e inventiOp will vbe apparent to} th'ose9 ski1iled "in the art as thesame becomes better 1111-,

'deristood by reference to the: followingd v 1 tailed descriptiop ftaken @in jLQIl-DGCtiOD With; the zmcqmpamyingdrawingsiiiewhichl hays at are known I and 1p yap e p invention isw, h e

- b0 thus formed pro vided with a j ve'rt i callongit'udihal partition: .18, forming rear illusigrated one "fpfad tife'ell and, approvlfl' IfnHi hedimem; 1 of "the invention, whepein a a FigLjjlisfaltop planview ofthejdevie; -'Ei g.;,2"is' a fronfi elevatidli, with the front hovel pla t efremoved. t ;diseleee interior; I

; i is'a vhOrigomaigseg' iim, w en the ine 3-,3; fig. 1, looking from ebeneathrgl,

Fig, A is'; wvertical sectio tziken p11 I Fig. f5;isgar;ver iCa i r' take? v rely in endvyelv fii I .rtly in A vler a e ie "taken/Q Ffg. 6, 1 2 ie :P

the end wall 15 c omprisin r in part a rela 75 tively wide b10 ek eenfire11y ,eeredgtef form; f an paesi g ;16 .thati"fcemmuiii datesdi T e t pump 1m"bellowsl of.the-instrument. The f ,v

front of"thelongitudinal pertition lfijapd" e, "between the end Wall; 14:7 am thebleck I15 is d'ivid ed byjaj transverse p artitien into' two-chambers 21.;tf1d22, IntqthetoP Wall) of the chamber 21is -ntered apip'e'QL' that leads fpq the ,wmd chesfl 'oqffthe instrument. h j p r it on' 8;i f i d i hor nt l 0h1 ng;p1;t= 23"- ,thgtfi ednpee ts thea ail passage I V 19gwithwthehambef';'22,e11(11;hisport is controlled ath l ottlel Va1ve 24, best-Shown in Figj25fwhic hya1ve isactl latedk'by 'pneu-; matiesqhereinaftep c les cct ibed; t9 Vary the size (of thejaip passage 'hetweenj the ;;clhambers 19' I and 22 .aridlthereby regfiil'ate' the intensity of};

the} suction draft'loreated ini thezwmd chestf group-0f;fr-pnemnatic, actions f sttuc tlirally ounted-upon'the 'casifighf similar. to the pneumatic actions coinmonly I ish pwxtthree "Such. p eumatic'accienspeomprise I I r k ng"iipeum i wi 11 6- 7, a

of these valves being connected by tubes 29, b0 and 31 to expression control openings in the tracker range (not shown) of. the instrument. As shown in Fig. 1, the upper swinging side of the pneumatic carries a lateral arm 32 th at overlies the upper swinging side of the adjacent pneumatic 26, so that when the pneumatic 25 is collapsed it :auses a corresponding collapse to the same extent of the adjacent pneumatic 26. To the upper swinging sides of the pneumatics 26 and 27 are secured forwardly projecting arms and 34 respectively, both of which directly overlie abutton 35 carried on the upper end of a rod 86 that extends downwardly through the valve housing and the top wall 12 of the casing, and is connected at its lower end by a pin 37 to the valve 2% one side ot the longitudinal center of the later. T he toldable side of the pneumatic 25 carries a forwardly projecting arm 38 in which is mounted an adjustable stop 39 by which the stroke of the pneumatic is regulated and limited. The arms 33 and 3st carry similar adjustable stops 40 and L1, respectively. The steps are so set that the pneumatic 25 has the shortest stroke; the pneumatic 26 has an intermediate stroke; and the pneumatic 27 has the longest stroke. Manitestly, when the pneumatic 25 is collapsed, it operates through the arm to simultaneously collapse the a acent pneumatic 26 to the same extent, and a latter through its arm 33 striking on the button 35 lowers the right hand end of the valve 24 to an extent permitted by the length of stroke of the pneumatic this latter be ing limited by the stop 39.

When the pneumatic 26 collapsed it acts independently of the other pneumatics to similarly affect the valve 24, lowering the latter to a somewhat greater extent per mitted by its stop 40. Likewise, when the pneumatic 27 is collapsed it acts to still turther lower the valve 24 to the maximum extent as permitted by its stop ll. This lowering oi? the valve 24 effects varying degrees of opening of the wind port or passage 23.

The pneumatic 25 thus controls the throttle valve 24L to produce a piano effect, the pneumatic 26 similarly controls the throttle valve 24. to produce a mezzo-forte etlect, and the pneumatic 2T similarly controls the throttle valve to produce the forte ettect. ln that portion of the partition wall 18 which divides the chamber 21 from the wind passage 19 is formed a port 42 controlled by a disc valve 43, this latter being fast on a valve stem a l that is slidably mounted at its front end in a bridge 45 and at its rear end in the rear wall. 10 oi. the casing, projecting through the latter and carrying; a button 416. This valve a3 is normally held closed by a spring 4.7 encircling its stem, and is opened by a pneumatic 48 mounted on the outer side of the rear wall. T his pneumatic 48 as best duct-s l9 and 50 with a die Jhra 'm through chamber 51 controlled by a valve 52, this-controlling mechanism of the pneumatic e8 being controlled by a hole in the tracker ran e through a tube 53.

shown in Fig. 5, communicates lVhen the pneumatic 418 is collapsed, it unseats the valve as thereby placing the wind chest of the PHQIEL matic action of the instrument in tree communication with the suction bellows through the relatively large port 42, thereby producing the double forte effect.

In the playing of most music records, vacuum existing in the wind chest of the player action tends to vary accordinp to the number of notes which are being played at successive intervals or periods as the music sheet travels over the tracker range. For instance, a passage containing a large number oat notes in both the treble and bass admits a considerable volume of air to the wind chest through the tracker holes and tubes and lowers the vacuum, with a consequent decrease in the "force or power with which the notes are sounded by the striking; pneumatics of the player action. On the other hand, a solo passage, or a rest or dwell between successive passages involves the admission of little or no air to the wind chest, so that the vacuum in the latter increase with a consequent increase in the power or force with which the notes, are sounded by the striking pneumatics. Hence, it is desirable to provide a stabilizer r pressure governor for the wind chest, which shall act automatically to maintain a substantially constant condition of the vacuum in the wind chest regardless of changes in the volume of sound caused by the note sounding apertures of the music record.

in the present invention I have provided such a stabilizer which acts directly upon the main throttle valve 24. To the underside of the casing is attached a pneumatic 54L, the lower movable side oi which is directly connected by a rod with the let hand end of the throttle valve 24:, thus giving to the latter the character of afloating throttle valve. To maintain this valve in close sliding contact with the wall in which its port 23 is formed it is pressed a 'ainst said wall by a depending spring: finger 56 attached at 5? to the top wall of a casing and lying: centrally crosswise of the valve 2 1. As shown in t, the interior oi? the pnein matic 534 communicates freely with the chairber 22 through the port 58.

To provide for an adjustable connection of the pneumatic 54: to the throttle valve through the rod 55, the lower movable side St of the pneumatic is slotted as the shown at 59, and across this slot extends a bridge 60 itself slotted. to permit the passage therethrough of the lower threaded end of the rod 55.v @n time latter is an ad- 1s tmp WhQimQWw ftheuwind chest if iecf 'var v or'itro" nged c hkm1; 71 t e; ur osgmw ic hen ullrdt wind-chest- WilL bafappgrefit when? it cq'nsi dered that- 13kg suddgn ffloodmg jo greater or 10f the other pnm passage 19, threby .p'an'ion pneumatic instxhfily acts'toi open saidpnetimatic'fthefeg I acts" with igrziter; strength- 1011 thg windjche t and "thu'sf counteracts "the? lowering; 30f v 1 125m 1 Ithrbttle valve 24 and incre'a sin the," "iefi'C pn e f hsitivefa ncl prompt s0 lit a'iits at all v I ftim e'sw tpf maintain{9QfsubstanriallyQ"cbnstantr* y "extendingf a low endf wall fgx tending;

" f rm d W -1 2.1; An} expression h bhr i m ew man re ctangular box-Rhohtaifiingfl a wind f ypassa-ge ibonnected1' at one, end? i0: 119 Wind phefstnnd a; the other. 611d tofhe ilhallstr 1 f a Iwall extending across said wind, passage fand formed withf-"a port; '1 a 1 throttle alve" amie controlling said port, an actuating rod for said valve; :1 spring acting: through said rod to urge said valve in port closing lirection a pair of expression pneumatic-s mounted e by side on the top of said adjust-able stops: differentially limiting the musical instruments, comprising; substan tially rectangular be}: containing a wind connected one end to the wind chest at the other end to the exhauster a wall extending: said wind passage and formed with a port t rottle valve controlling; port an acti ting rod for said valve extending upwardl through the top wall of said box, a spring acting through said rod to urge said valve in port closii direction a group of three expression pneumatics mounted side hv side on the top of said box, adjustable stops differentially limitingthe power Sl-l'Ol -IQS of said pneumatics, a pair of arms respectively attached to the movable sides of the center and one side pneumatic and both serv ng to strike and move said valve actuating rod in a direction to shift said valve in port opening directiom andan arm at ached to the movable side of the other side pneumatic overlying: and serving to depress the movable sideot the center pneumatic.

d. An. expression device lor self-playing musical instruments, comprising box containino' a wind passage connected at one end to theivind-chest and at its other end to the exhausteij a wall extending aeross said wind e and illlefil with a port, a fiat throttle valve pivoted at one end in sliding;

contact with said well and partly covering; said port a valve-acti ting rod pivoted at its lower end to the other end of said valve and extending throuqh thetop wall of said been a sprin 11 said rod in an upward direction a urality of pneumatics mounted on the top wall of said box, striker arms carried by the movable sides of said pneumatics to depress said roch and adjustable stops 7 liuitiup the strokes of said pneuma tics.

end in the wind chest and at the other end nected to the other end of said throttle valve and operating to swing the latter in a direction. to further uncover said port, a valve disc movable toward and from the other of said ports, a spring urging said valve disc to port-closing position, and a pneumatic mounted on said box and operating to unseat said valve disc and open said port.

6. in expression device for self-playing musical instruments, comprising a box containing a. wind passage connected at one end to the wind chest and at the other end to the exhauster, a wall extending across said wind passage and formed with two independent ports, a throttle valve pivoted at one end in sliding contact with said wall and partly covering one of said ports, a group of pneumatics mounted on said box and connected to the other end of said throttle valve and operating to swing the latter to varying extents in a direction to :t'urther uncover said port, whereby to produce piano, mezzo forte and forte effects, valve disc movable toward and from the other of said ports, a. spring urging said valve disc to port-closing position, and a pneumatic mounted on said box and operating to unseat said valve disc and open said port whereby to produce a, double forte effect. I

7. In an expression device for self-playin i struments, the combination of a sub s lially rectangular box containing a wind passage connected at one end to the wind chest and at the other to the eXhauster, a throttle valve controlling said wind passage, a spring urging said valve in a: direction to throttle said wind passage, a plurality of expression pneumatics mounted on the top wall of: the said box, mechanism differentially operated by said expression pneumatics for moving said valve in a direction to open said wind passage a pressure governing pneumatic mounted on the lower side of said box in constant communication with said wind passage, a spring opposing collapsing movement of said governin pneumatic, and a connection between said goveniing pneumatic and said valve by which a collapsing; movement of the former transmits a passage-restricting movement to the latter.

OSCAR A. ERICSON. 

